Re: Derivatives
- To: mathgroup at smc.vnet.net
- Subject: [mg113727] Re: Derivatives
- From: Murray Eisenberg <murray at math.umass.edu>
- Date: Tue, 9 Nov 2010 03:53:28 -0500 (EST)
I think you're asking whether Mathematica can do implicit differentiation. The answer is yes. Here's a rather simple example. eq n= y x^4+4x^2 y+x^ 3== 8 ; neweqn = eqn /. y - >y[x] ; deriveqn = D[neweqn, x] derivative = y'[x]/.First@Solve[deriveqn, y'[x]] yvalue = y /. First@Solve[eqn, y] derivative /. y[x] - >yvalue On 11/8/2010 3:37 AM, will wrote: > Hello, > > I am trying to take the derivative (d/dx) of a very messy equation > that is more easily expressed initially as a function of y, then y and > a function of x. Rather than have to substitute and expand, can a set > of equations be input and instructed to find a derivative wrt x? > > (A little bit new to Mathematica) > > Thanks. > Will > -- Murray Eisenberg murray at math.umass.edu Mathematics & Statistics Dept. Lederle Graduate Research Tower phone 413 549-1020 (H) University of Massachusetts 413 545-2859 (W) 710 North Pleasant Street fax 413 545-1801 Amherst, MA 01003-9305